On Management of Free Space in Compressed Memory Systems

Copyright [©] (1999) by Association for Computing Machinery, Inc. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distrubuted for profit or commericial advantage. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee.

This paper considers issues relevant to Operating System control of systems with compressed main memory. The notion of allocated but unused storage is introduced. This represents storage which has been recently allocated by the Operating System, but which does not yet occupy physical memory because the lines have not yet been cast out of the cache. We propose that control policies incorporate estimates of allocated but unused storage, as such storage represents major way in which compressibility can dramatically change.The paper addresses the estimation of allocated but unused storageand analyzes its accuracy on system traces.

By: Peter A. Franaszek, Philip Heidelberger, Michael Wazlowski

Published in: ACM Performance Evaluation Review, volume 27, (no 1), pages 113-21 in 1999

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